This invention relates to aircraft cargo handling systems and more particularly to apparatus for rapid installation of a cargo ramp of the type which is deployed between an aircraft cargo opening and the ground to facilitate the loading and unloading of vehicles, pallatized cargo and other cargo of a general nature.
Large cargo carrying aircraft often utilize an inclined ramp structure that is extendable between the sill region of the aircraft cargo opening and the ground to facilitate loading and unloading of the aircraft. One such cargo ramp, which can be carried onboard an aircraft and easily deployed through a cargo opening formed by an upwardly swingable nose section of the aircraft, is disclosed in U.S. Pat. No. 4,039,163, such patent having issued to the Applicant named herein and being assigned to the assignee of this application.
Although each embodiment of the cargo ramp disclosed and claimed in the aforementioned patent, is specifically arranged for storage within the aircraft cargo compartment and is arranged for structural coaction with components of the aircraft cargo system to provide rapid deployment between the aircraft cargo opening and the ground, it is sometimes necessary or desirable to remove such a cargo ramp from the aircraft or load such a cargo ramp onto an aircraft. Such loading and unloading operations must be undertaken, for example, if a cargo ramp is to be replaced or removed for repair and maintenance operations. Further, in operating a sizable fleet of cargo aircraft, it could be advantageous to operate with a number of cargo ramps that is less than the number of aircraft being operated. In this regard, a cargo ramp could be installed and carried aboard an aircraft during flights in which a cargo ramp or other cargo loading system is not available at the aircraft's destination. On the other hand, when a cargo ramp is available at the aircraft's destination, the cargo ramp utilized for loading the aircraft could be disconnected and left at the point of departure with another cargo ramp being installed to the aircraft for the unloading operation.
It will be recognized that the potential benefits of such a procedure include minimizing the investment required to maintain an adequate cargo handling system and, since a cargo ramp need not be carried on all flights, an increase in the cargo carrying capacity of the aircraft or, if the increased capacity is not utilized, a decrease in the gross weight of the aircraft. However, these potential advantages can only be realized if equipment is available to rapidly install the cargo ramp to the aircraft and to rapidly disconnect the cargo ramp whenever the ramp will not be required at the aircraft's destination. In particular, in both commercial and military applications, efficient utilization of the aircraft demands that cargo be loaded and unloaded as quickly as possible. Further, in military applications in which cargo is loaded or unloaded under conditions in which the aircraft may be exposed to enemy action, it is highly desirable to minimize the amount of time that the aircraft is on the ground.
Since cargo ramps such as those described in the above-referenced patent extend from the cargo opening sill region, which is located a considerable distance above ground level, and since such cargo ramps are constructed to bear the weight of heavy cargo such as vehicles, the cargo ramps are both quite bulky and heavy. Thus, conventional ground support equipment is generally not satisfactory for rapidly moving the upper end of a cargo ramp into and out of engagement with the aircraft. Further, attempts to utilize conventional apparatus could easily result in damage to the aircraft if the upper end of the cargo ramp were accidently allowed to strike the aircraft sill region during such operations.
Although special ground support equipment could be designed to effect satisfactory operation, such equipment would appear to present several disadvantages and drawbacks. For example, because of the relatively high sill height of the aircraft cargo opening and the weight of the cargo ramp, such ground support equipment would necessarily be rather massive or, in the alternative, require extendable stabilizers to allow the equipment to lift the upper end of the cargo ramp into and out of position. Further, such ground support equipment would generally not only require power driven apparatus for lifting a cargo ramp, but would also require a propulsion system so that the equipment could be moved about between various aircraft.